Furnace valve water seal



July 25, 1961 P. H. NELISSEN FURNACE VALVE WATER SEAL Filed May 22, 1959 Arran/Vey United States Patent O 2,993,501 FURNACE VALVE WATER SEAL Peter H. Nelissen, R.F.D. 4, Box 381, Valparaiso, Ind. Filed May 22, 1959, Ser. No. 815,171 4 Claims. (Cl. 137-251) 'I'his invention relates to metal reheating furnaces that use blast furnace gas as a fuel and, as indicated, to a Water 'seal for a valve controlling' the supply of fuel gas to the furnace.

The invention is particularly Iapplicable to ingot soaking pits. When relining or repair of a furnace of this character is required, leakage of gas into the furnace must be prevented. For this purpose the conduit that supplies the gas to the furnace burner is provided with a control valve that is operated to its closed position, and to prevent leakage of gas through the closed valve, a water seal is commonly provided by filling a portion of the supply line in advance of the control valve with water, and conventional apparatus for this purpose has usually included a mechanism for visually indicating that the line in advance of the control valve has been lled with water to a desired level. However, such apparatus has proved unsatisfactory in practice by reason of faulty operations furnishing a false indication that the water seal has been effected when in fact no Water is present in advance of the closure valve thus enabling gas to leak through the valve.

One of the principal objects of this invention is to provide an improved water seal for furnace valves that will not furnish a false indication of the character mentioned above. Other objects and advantages of the invention will become apparent from the following description and accompanying drawing in which:

FIGURE l shows somewhat diagrammatically a preferred embodiment of the invention as applied to a blast furnace gas supply line for an ingot soaking pit; and

FIGURE 2 is an enlarged view of the water sealing apparatus shown in FIGURE 1.

A fragmentary portion of a conventional soaking pit is shown diagrammatically in FIGURE 1 as comprising a heating furnace 1 and a recuperator 2 at one side of the furnace 1 The furnace 1 is heated by a gas burner 3 opening through the floor 4 of the furnace. The burner 3 is supplied with blast furnace gas through the horizontally extending conduit 5 which is connected at its outer end to a vertically extending supply line 6. The upper end of the line 6 receives blast furnace gas from a supply main 7. A closure valve 8 in the conduit 5 controls the flow of gas therethrough to the burner 3. The bottom of the supply line 6 extends below its connection to the conduit 5 and is connected by a closure valve 9 to a drain 10. 'Ihe lower end of the drain 10 is connected with an upwardly extending pipe 11 which has a reverse bend 12 at its upper end connecting it with a downwardly extending pipe 13 which terminates at a point above a funnelshaped sewage outlet 14. By reason of the spacing of the lower end of the pipe 13 with respect to Ilthe outlet 14, a visual indication is furnished whenever Water is owing through the drain 10.

In accordance with the principles of this invention an overflow conduit 15 is connected into the supply line 6 at a point 16 which is spaced vertically above its point of connection to the horizontal conduit 5. A valve 17 controls the ow of fluid through the conduit 15 which has its lower end connected at 18 into the drain 10 at a point just below the closure valve 9.

A water supply pipe 19 has a connection 20 into the gas lsupply line 6 preferably at a point, as illustrated, above the connection of the line 6 to the conduit 5 but below its connection 16 with the overflow conduit 15. As best shown in FIGURE 2, the inner end of the pipe 19 has a downwardly opening L-tting 21 so that water delivered therethrough will be directed downwardly toward the bottom of the line 6 `and can thus be used for flushing dirt through the drain valve 9. A valve 22 controls the admission of water through the water supply pipe 19.

In normal operation of the furnace, the gas valve 8 is open, the drain valve 9 and overow valve 17 are open, and the water supply valve 22 is closed. If flushing of the lower end of the line 6 is needed, the water supply valve 22 is opened to admit water to the line 6 which is discharged through the ilush valve 9 and the pipes 10, 11, 12 and 13. By reason of the arrangement of these pipes, it will be -apparent that a water trap is provided in the lower ends of the pipes 10 and 11 that prevents the escape of gas from the supply line 6, and in this respect it will be noted further that the reverse bend 12 is located at a level below the junction of the gas conduit 5 and gas supply line 6 so that flush water will not back up into the conduit 5. In practice, the valve 22 is open at all times so that the flushing operation is continuous while gas is being supplied from the line 6 to the conduit 5. When furnace repair is required, the gas valve 8 is closed, and the water supply valve 22 is opened to admit water continuously into the line 6 through the water supply pipe 19, The flush valve 9 must of course be closed in order 'that the lower end of the line 6 and the portion of the conduit 5 in advance of the gas valve 8 wil-l be lled with water. When the level of water rises in the -line 6 to the overflow opening 16, it will be drained off through the overflow pipe 15 and delivered to the drain outlet 14 through the drain pipe connections 10-13, and will thus furnish a visual indication that the valve 8 has been sealed by Water against the leakage of blast furnace gas therethrough.

While one embodiment of my invention has been shown and described it will be apparent that other adaptations and modifications may be made without departing from the `scope of the following claims.

I claim:

1. A water-seal for gas-fired furnaces comprising, the combination with a. conduit for supplying fuel gas to a furnace, and a shut-off valve in said conduit, of a vertically extending gas supply line having a connection at its lower end with said conduit and a water overow opening therein at a vertical level above said shut-off valve, a drain in the bottom of said supply line for discharging water therefrom, a pipe for continuously admitting water into said supply line, a valve in said drain for interrupting the ow of water therethrough to ll said supply line with water to the level of said overflow opening when the said shut-off valve is closed, and means connected with said overflow opening for indicating that water is flowing therethrough and that said supply line is filled with water to said vertical level.

2. A water seal as dened in claim l characterized by said last named means including an overflow conduit connecting said overllow opening with said drain at a point outwardly of said drain valve.

3. A water-seal for gas-red furnaces comprising, the combination with a conduit for supplying fuel gas to a furnace, and a shut-off valve in said conduit, of a vertically extending gas supply line having a connection at its lower end with said conduit and a water overflow opening therein at a vertical level above said shut-olf valve, a downwardly extending drain pipe having its upper end connected to the bottom of said supply line for discharging Water therefrom, means providing for the discharge of water from said drain pipe comprising a discharge pipe connected with the lower end of said drain pipe and extending in an upward direction therefrom, and an outlet pipe extending downwardly relative to said discharge pipe and having a connection at its upper end with the upper end of said discharge pipe, said discharge pipe and outlet pipe cooperating to provide a Water trap at a vertical level below said gas conduit and supply line connection for preventing the escape of gas from said supply line through said drain pipe, a pipe for continuously admitting water into said supply line, a valve in said drain pipe for interrupting the ow of Water therethrough to ll said supply line with Water to the level of said Yoverow opening when -the said shut-o valve is closed, and means connected With said overow opening for indicating that Water is flowing therethrough and that said supply line is filled With Water t0 said vertical level.

4. A water seal as delined in claim 3 characterized by said last named means including an overow conduit connecting said overow opening with said drain pipe at a point below said drain valve.

References Cited'in the file of this patent UNITED STATES PATENTS 934,447 Lea Sept. 21, 1909 1,266,509 McKee May 14, 1918 1,606,461 Williamson Nov. 9, 1926 1,609,525 Moldenhauer Dec. 7, 1926 1,858,986 Davis May 17, 1932 2,792,070 Strunk May 14, 1957 

